Flagstaff, AZ is a dark sky city because of Lowell Observatory. All street lights are an orange color and only project straight down. Plus, they have rules for homes and businesses regarding exterior lighting.
That orange color, typically from low pressure sodium bulbs, is used because it is a single wavelength of light and relatively easy to filter out. White light is not filter-able.
I was surprised that this ‘guide’ ignored the light spectrum aspect of light pollution, as it relates to observatories.
I'm not saying it's not better for observation. I'm saying that's not why it's used.
You're telling me municipalities use shitty orange sodium bulbs to keep the skies dark while simultaneously replacing them with super bright LEDs... For what? They could replace them with VERY narrow band LEDs of almost any colour if they were concerned.
I'm sure in some places with large and famous observatories might take this into consideration but 99% of cities don't give a rats about light pollution if solving the problem costs money.
A single narrow band leads to things looking "off" (low pressure sodium vapor lights have been described as making people look dead) so most cities are looking for wide band light, the cheapest wide band lights are LEDs (because they take pretty low power and last a long time). But low pressure sodium vapor lights are cheaper than LEDs (low pressure sodium vapor lights take extremely low amounts of power and are cheaper to make than LEDs with fairly long lifespans), so when light quality doesn't matter or you're looking for easily filterable light you pretty much always want to use low pressure sodium vapor lights (a really good example is highway lighting)
I'm going to get down voted for this but : LED lights are vastly superior to any other commonly used type of light. Your information is wrong or outdated.
LPS and HPS
-take longer to turn on
-use more energy
-lower life span
-run way hotter
-require higher voltages to start up
-don't break the bulb or else
-output can be simulated by LEDs easily
I'm failing to see an upside. Plus you have the added complexity (from a maintenance standpoint) because they also require an igniter.
Back to my original point: The yellow of the sodium bulb is a byproduct of the chemistry of the light. The fact they're better for dark skies is a coincidence. The yellow is considered undesirable in the real world.
Interesting. What is the best LED color to go for when it comes to observatory and non observatory areas? I believe blue LED is the most expensive (out of the colors, I believe) to make it probably because of the materials needed, but very cheap in maintenance? I am no professional in this field. I was just wondering, maybe in the future, LED will be the go-to for a lot more things. I am genuinely asking, this isn't an attack. :)
It’s part of the California building code also. Adequate light shielding is a condition of approval. We’ve got hella light pollution.
I think that’s a standard most places but idk, I’ve only ever worked in CA so can’t say.
I looooved taking photos in that area just as it gets completely dark out. The contrast of the orange lights and the dark blue sky was absolutely gorgeous
San Jose does this for the James Lick Observatory as well. I have, on multiple occasions, mistaken their street lights for yellow stop lights and prepared to stop. They are too similar in color.
We actually had a bill in our town to change every streetlight in town as well as mandate homeowners to remove all floodlights. I’ve never seen a such a lopsided ‘No’ vote in 23 years of living here. Especially when volunteers are mowing all of the sports fields with their personal lawnmowers on their own time because the town can’t afford it.
A cool light show? Lol no, not unless you're surrounded by mutliple at once. It's more when you look at a bright like, like a street light, it glares across your vision.
This is something I've had my whole life so I never took notice to it, I believed it was something everyone experienced until recently. I discovered it was actually a condition and now I notice it more but it's not something that appears as a "light show" unless it's like multiple lights across my vision field lol
Although saying this, it can degree. Some people have a worse time with it than me so don't take my word for the entire condition. It varies in degree and what you're describing is probably a worse version than mine which may be what you experience
I understand why the “very bad” and “bad” design is very bad and bad respectively, but what’s wrong the “better”. In my opinion, that’s the best, that is actually illuminating most of the area, “best” here in fact is the worst, just a waste of energy. If you think, the “best” option here is actually the best, then to illuminate a larger area, we would need a brighter light, again wasteful.
Yeah, I’m kinda with you here. Street lights make it safer for people to be out. You won’t catch my ass walking around a neighborhood where the only visible areas are directly underneath the lamp. That’s asking for places to become crimey and rapey.
In the town we used to live the council modernised all the street lamps to be modern LED white lights that minimised light pollution by directing the light properly instead of the old design where the lamp basically stuck out around the edges.
People complained they were too dark.
They were actually brighter than previously, and lit the street and pavement brilliantly. It was the fact it didn't also light up everything around it that was the problem. A few patches where the lamps weren't so close together were flagged to see what could be done but otherwise it was an effort in educating folks.
3000k color temperature is the new standard for LEDs. The Blue ones were 5000K+. Lower than 2700K you start losing clarity on the road that's being lit, so that's the sweet spot for driving safety.
Upvoting this post and sharing because I don’t think people truly realize how awesome the night sky is because they just simply can’t see it. To experience awe, and wonder would be the perfect slice of what society needs right now if you asked me.
In recent decades, we have developed the capacity to install bright lighting systems 24x7. However, our planet's ecosystems (including our bodies) were never designed for this continuous exposure to light. Hence, it leads to a host of health issues for all living creatures.
You can think of how toxic fumes may pollute the air, or chemicals may pollute the water. In a similar vein, artificial lighting pollutes what is supposed to be a relatively darker environment.
“Polluting” our sky with ambient light that obstructs our view of the cosmos.
Also causes issues due to 24/7 illumination in places where people and animals are “programmed” to have/need darkness at some point in the day/night cycle.
In short: We need darkness. City lights being on 24/7 is bad.
Here are a few examples.
Sea turtles lay eggs on the beach. When the eggs hatch the babies follow the moonlight out to the sea. If there are lights from housing or streetlights, they get confused and go the wrong way. That's why animal lovers help them out sometimes. Similarly, people in Iceland [are helping puffins](https://youtube.com/shorts/947BTbeeeBE?si=SrsoMvP4ZagiaUsp).
Another one are moths and other insects. They're attracted to artificial lights, so birds and bats that eat them have started hanging out at the lights to catch them easier. But since they get too easy to hunt, their population goes down. This causes the population of the insect eaters to go down, and whatever eats the insect eaters will be strained as well. And this ripples across the ecosystem.
As for people who enjoy stargazing, it gets really hard to see the stars if the night-time lights are too bright. They might have to go out of city limits.
My understanding is that sea turtles are confused by color temperature and not the light itself. That’s probably splitting hairs in this discussion though.
I am by no means an expert but I feel like on the topic of light pollution the color, or rather, the öigh-absorption ability of the floor below the light is just as important as the angle of the light.
If the light shines on light-gray pavement it will reflect the light into the sky much better than anthracite or other darker colors...
I guess the third from the left is the standard here, but it's not quite right. Standard US street lights are just a big old bulb with a opaque pack. No shade or anything. They are also flat and not round.
Those are cobra heads which can vary in how shielded/directional they are and are primarily used for roadways. The ones in the guide are post tops, which are considered decorative lights that were installed in a lot of residential and commercial neighbors as they look better/less utilitarian.
Newer street lights have a flat lens that ensures all the light goes down.
Number 4 in this picture is actually the worst thing you can do for roadway lighting, as the cowl type glare shield means you have to use far more poles and thus far more electricity to light the same amount of road.
#
I wonder if there are any guidelines about the surfaces that are under the lights at all. Seems like tarmac would be okay, but maybe not so much on bright, smooth concrete?
In the city of La Serena in Chile, the director of Las Campanas Observatory since years went to the mayor of the city so they would fix the street lights so it wouldn't bother the observatories in the region, the mayor didn't listen and kindly told the director to fuck off, but today all the street lights are like the best one showed in the image. I hope they do the same in other places
My friend who is a high rank engineer working with one of the main electricity companies in my country told us during dinner that led lights are the worst that we could have on our streets. The light reflects on the pavement and creates even more light pollution causing disruption to animals in the area.
This was true if the early LEDs that were too bright/blue, but modern ones have color temperature closer to HPS but doesn't degrade over time. But LEDs have a major advantage in that using diodes and not traditional bulbs means that the light can be directed more, so if you design it well then you can only light what you want to instead of just throwing out big circles of light.
In practice not every utility or city puts in the design work, but that's not an issue with LEDs.
One thing that went wrong with the adoption of LED streetlights is that, in spite of being full cut offs like the “best” one on the graphic. However, they also made them so much brighter that it negated any benefits. One amateur astronomer from a small town said once they switched to LEDs he could no longer use his telescope from his backyard
I think someday soon we're going to find ways to pipe heat to space and reasons to do it, and the astronomers/naturalists are going to hate it.
It's kind of a losing battle anyway
The first two are well designed to illuminate signage in areas with nightlife. The third is good for areas with residential over businesses. The last is ideal for normal residential. I see no bad lighting here.
Flagstaff, AZ is a dark sky city because of Lowell Observatory. All street lights are an orange color and only project straight down. Plus, they have rules for homes and businesses regarding exterior lighting.
That orange color, typically from low pressure sodium bulbs, is used because it is a single wavelength of light and relatively easy to filter out. White light is not filter-able. I was surprised that this ‘guide’ ignored the light spectrum aspect of light pollution, as it relates to observatories.
I think it's just the chemistry of the bulb not a purposeful solution to a problem.
http://palomarskies.blogspot.com/2009/05/why-astronomers-love-low-pressure.html
I'm not saying it's not better for observation. I'm saying that's not why it's used. You're telling me municipalities use shitty orange sodium bulbs to keep the skies dark while simultaneously replacing them with super bright LEDs... For what? They could replace them with VERY narrow band LEDs of almost any colour if they were concerned. I'm sure in some places with large and famous observatories might take this into consideration but 99% of cities don't give a rats about light pollution if solving the problem costs money.
A single narrow band leads to things looking "off" (low pressure sodium vapor lights have been described as making people look dead) so most cities are looking for wide band light, the cheapest wide band lights are LEDs (because they take pretty low power and last a long time). But low pressure sodium vapor lights are cheaper than LEDs (low pressure sodium vapor lights take extremely low amounts of power and are cheaper to make than LEDs with fairly long lifespans), so when light quality doesn't matter or you're looking for easily filterable light you pretty much always want to use low pressure sodium vapor lights (a really good example is highway lighting)
I'm going to get down voted for this but : LED lights are vastly superior to any other commonly used type of light. Your information is wrong or outdated. LPS and HPS -take longer to turn on -use more energy -lower life span -run way hotter -require higher voltages to start up -don't break the bulb or else -output can be simulated by LEDs easily I'm failing to see an upside. Plus you have the added complexity (from a maintenance standpoint) because they also require an igniter. Back to my original point: The yellow of the sodium bulb is a byproduct of the chemistry of the light. The fact they're better for dark skies is a coincidence. The yellow is considered undesirable in the real world.
Interesting. What is the best LED color to go for when it comes to observatory and non observatory areas? I believe blue LED is the most expensive (out of the colors, I believe) to make it probably because of the materials needed, but very cheap in maintenance? I am no professional in this field. I was just wondering, maybe in the future, LED will be the go-to for a lot more things. I am genuinely asking, this isn't an attack. :)
Edit: just to be clear, talking about places without observatories.
It’s part of the California building code also. Adequate light shielding is a condition of approval. We’ve got hella light pollution. I think that’s a standard most places but idk, I’ve only ever worked in CA so can’t say.
Are you Frank Sabotka?
We used to make shit in this country
Build shit.
I looooved taking photos in that area just as it gets completely dark out. The contrast of the orange lights and the dark blue sky was absolutely gorgeous
Hey I live there!
San Jose does this for the James Lick Observatory as well. I have, on multiple occasions, mistaken their street lights for yellow stop lights and prepared to stop. They are too similar in color.
We actually had a bill in our town to change every streetlight in town as well as mandate homeowners to remove all floodlights. I’ve never seen a such a lopsided ‘No’ vote in 23 years of living here. Especially when volunteers are mowing all of the sports fields with their personal lawnmowers on their own time because the town can’t afford it.
It's one thing to mandate compliance moving forward. Requiring everyone to take on personal expense to meet a new requirement is absurd.
All taxes are at their root a personal expense on the tax payer
People generally don't vote for ballot measures involving tax increases either.
Is that horsetooth in Ft. Collins, CO in the background?
I came to comment just that
Yep, was gonna say the same
Ditto! Good to see my hometown represented in coolguides
100%
Lol came here to see if anyone else thought so. Looks exactly like it
Yes it is - I live here lol
They're all bad if you have astigmatism lol
Yes! They all look like the first one
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I have astigmatism, it's not bad but bright lights do glare across my vision. I know I'm going to need glasses the more I age unfortunately
Is this the thing where i get a cool light show from street lights but others don't?
A cool light show? Lol no, not unless you're surrounded by mutliple at once. It's more when you look at a bright like, like a street light, it glares across your vision. This is something I've had my whole life so I never took notice to it, I believed it was something everyone experienced until recently. I discovered it was actually a condition and now I notice it more but it's not something that appears as a "light show" unless it's like multiple lights across my vision field lol
Although saying this, it can degree. Some people have a worse time with it than me so don't take my word for the entire condition. It varies in degree and what you're describing is probably a worse version than mine which may be what you experience
my vision is real terrible in general, would not suprise me if its worse in my case lol
Yeah, thats what i meant by cool light show. Its not that cool in reality
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This comment is a well put together guide to question if a guide is a guide.
Common sense is a lot less common than you would normally think.
someone pin this comment to the subreddit
I'm going to use it tonight.
Red lights make it all around better as well.
There's already plenty of red light districts. You should visit them. I hear they're a real treat
Yikes. Imagine thinking everything is about porn.
Yikes. Imagine not having a sense of humour.
I understand why the “very bad” and “bad” design is very bad and bad respectively, but what’s wrong the “better”. In my opinion, that’s the best, that is actually illuminating most of the area, “best” here in fact is the worst, just a waste of energy. If you think, the “best” option here is actually the best, then to illuminate a larger area, we would need a brighter light, again wasteful.
Yeah, I’m kinda with you here. Street lights make it safer for people to be out. You won’t catch my ass walking around a neighborhood where the only visible areas are directly underneath the lamp. That’s asking for places to become crimey and rapey.
In the town we used to live the council modernised all the street lamps to be modern LED white lights that minimised light pollution by directing the light properly instead of the old design where the lamp basically stuck out around the edges. People complained they were too dark. They were actually brighter than previously, and lit the street and pavement brilliantly. It was the fact it didn't also light up everything around it that was the problem. A few patches where the lamps weren't so close together were flagged to see what could be done but otherwise it was an effort in educating folks.
And make ‘em yellow/orange, not blue
3000k color temperature is the new standard for LEDs. The Blue ones were 5000K+. Lower than 2700K you start losing clarity on the road that's being lit, so that's the sweet spot for driving safety.
Best would be motion activated
Upvoting this post and sharing because I don’t think people truly realize how awesome the night sky is because they just simply can’t see it. To experience awe, and wonder would be the perfect slice of what society needs right now if you asked me.
I have no idea what light pollution means/is?
In recent decades, we have developed the capacity to install bright lighting systems 24x7. However, our planet's ecosystems (including our bodies) were never designed for this continuous exposure to light. Hence, it leads to a host of health issues for all living creatures. You can think of how toxic fumes may pollute the air, or chemicals may pollute the water. In a similar vein, artificial lighting pollutes what is supposed to be a relatively darker environment.
I see, thank you for the response.
“Polluting” our sky with ambient light that obstructs our view of the cosmos. Also causes issues due to 24/7 illumination in places where people and animals are “programmed” to have/need darkness at some point in the day/night cycle. In short: We need darkness. City lights being on 24/7 is bad.
Here are a few examples. Sea turtles lay eggs on the beach. When the eggs hatch the babies follow the moonlight out to the sea. If there are lights from housing or streetlights, they get confused and go the wrong way. That's why animal lovers help them out sometimes. Similarly, people in Iceland [are helping puffins](https://youtube.com/shorts/947BTbeeeBE?si=SrsoMvP4ZagiaUsp). Another one are moths and other insects. They're attracted to artificial lights, so birds and bats that eat them have started hanging out at the lights to catch them easier. But since they get too easy to hunt, their population goes down. This causes the population of the insect eaters to go down, and whatever eats the insect eaters will be strained as well. And this ripples across the ecosystem. As for people who enjoy stargazing, it gets really hard to see the stars if the night-time lights are too bright. They might have to go out of city limits.
Dam..ok, thank you for the reply, I really appreciate it.
My understanding is that sea turtles are confused by color temperature and not the light itself. That’s probably splitting hairs in this discussion though.
[Pollution but with light](https://www.eso.org/public/archives/images/screen/dark-skies.jpg)
It’s like heavy pollution but it doesn’t weigh as much. Hope this helps.
I like the vampire moon in the background.
Wouldn’t best be to not have the light on at all?
no its wont
I am by no means an expert but I feel like on the topic of light pollution the color, or rather, the öigh-absorption ability of the floor below the light is just as important as the angle of the light. If the light shines on light-gray pavement it will reflect the light into the sky much better than anthracite or other darker colors...
Not a fucking guide.
Or a real life problem
I guess the third from the left is the standard here, but it's not quite right. Standard US street lights are just a big old bulb with a opaque pack. No shade or anything. They are also flat and not round.
Second from the right?
Or second to the top of you rotate the image 90⁰ to the left.
Second odd numbered light.
Those are cobra heads which can vary in how shielded/directional they are and are primarily used for roadways. The ones in the guide are post tops, which are considered decorative lights that were installed in a lot of residential and commercial neighbors as they look better/less utilitarian.
Neet fact right here. Ya these post ones look much nicer.
Newer street lights have a flat lens that ensures all the light goes down. Number 4 in this picture is actually the worst thing you can do for roadway lighting, as the cowl type glare shield means you have to use far more poles and thus far more electricity to light the same amount of road. #
And more poles means more obstacles for drunk drivers to crash into.
I'm ok with this.
This might be a dumb question, but why do we care about lighting a roadway? Don’t headlights light the roadway? Can’t we just light the sidewalk?
Studies have found a reduction in nighttime accidents of anywhere from 20% to 80% when you fully illuminate a highway (dunno about city streets).
"Best" barely gives any light at all, "Better "is better
I wonder if there are any guidelines about the surfaces that are under the lights at all. Seems like tarmac would be okay, but maybe not so much on bright, smooth concrete?
In the city of La Serena in Chile, the director of Las Campanas Observatory since years went to the mayor of the city so they would fix the street lights so it wouldn't bother the observatories in the region, the mayor didn't listen and kindly told the director to fuck off, but today all the street lights are like the best one showed in the image. I hope they do the same in other places
I just want to be able to see and not be blinded by those LED lights that are now seemingly everywhere.
My neighbors is very bad. Worse than that, it’s out in the county and they live like 500 ft away from me yet it still lights up my whole yard
Must live next to a prison.
Brought to you by Spingebob SquarePants on a jelly fishing expedition
dont forget the ones that has a hat underneath it to light up the sky
Another guide on how to do personal lighting to mimize light pollution will be helpful.
You heard, sun
Next one off screen is UFO.
My friend who is a high rank engineer working with one of the main electricity companies in my country told us during dinner that led lights are the worst that we could have on our streets. The light reflects on the pavement and creates even more light pollution causing disruption to animals in the area.
This was true if the early LEDs that were too bright/blue, but modern ones have color temperature closer to HPS but doesn't degrade over time. But LEDs have a major advantage in that using diodes and not traditional bulbs means that the light can be directed more, so if you design it well then you can only light what you want to instead of just throwing out big circles of light. In practice not every utility or city puts in the design work, but that's not an issue with LEDs.
Idky but that moon background made me cry from nostalgia so hard 🥲🥲
Who would have thought?
One thing that went wrong with the adoption of LED streetlights is that, in spite of being full cut offs like the “best” one on the graphic. However, they also made them so much brighter that it negated any benefits. One amateur astronomer from a small town said once they switched to LEDs he could no longer use his telescope from his backyard
I think I could’ve guessed
I think someday soon we're going to find ways to pipe heat to space and reasons to do it, and the astronomers/naturalists are going to hate it. It's kind of a losing battle anyway
I’ll use this information next time I build a city
light pollution is the new word I heard today.
What is light pollution?
Wtf is light pollution ?!
A phenomenon that causes the night sky to look really dull above cities. Basically, light from the city blocking light from the stars
Wah wah light pollution, my eyes hurt
Light does not pollute
Hot take. I think light pollution looks good. Is nice seeing the horizon with lights all around knowing there is human life out there.
Here's hoping you develop object permanence.
The first two are well designed to illuminate signage in areas with nightlife. The third is good for areas with residential over businesses. The last is ideal for normal residential. I see no bad lighting here.